(CNN/CBS) -- Planes and ships from around the world are searching the Indian ocean, west of Australia for any sign of Flight 370.
They were words heard around the world as investigators searched for the missing Malaysia Airlines plane.
Weeks ago, Malaysian authorities said the last message from the airplane cockpit was, "All right, good night."
The sign-off to air traffic controllers, which investigators said was spoken by the plane's copilot, was among the few concrete details officials released in a mystery that's baffled investigators since the Boeing 777 disappeared with 239 people aboard on March 8.
Malaysian authorities gave no explanation for the discrepancy between the two quotes. And authorities are still trying to determine whether it was the plane's pilot or copilot who said them.
The final quote is routine and is not a sign that anything untoward occurred aboard the flight, said CNN aviation analyst Mary Schiavo.
But the change in wording weeks into the search for the missing plane raises questions about how Malaysian officials have handled the investigation.
"It speaks to credibility issues, unfortunately," Schiavo said.
"We haven't had a straight, clear word that we can have a lot of fidelity in," said Michael Goldfarb, former chief of staff at the U.S. Federal Aviation Administration. "We have the tragedy of the crash, we have the tragedy of an investigation gone awry and then we have questions about where we go from here."
Malaysian authorities have defended their handling of the situation.
Acting Transportation Minister Hishammuddin Hussein said Monday that authorities were not hiding anything by declining to release some details of the missing flight. Some details are part of ongoing investigations into what happened to the plane, he said.
"We are not hiding anything," he said. "We are just following the procedure that is being set."
Hussein said the transcript released Tuesday offered "no indication of anything abnormal."